package cn.tedu.sp16zuul.fb;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

@Component
public class ItemFB implements FallbackProvider {
    /**
     * 设置针对那个后台服务进行降级
     *  -item-service  ： 只对商品服务降级
     *  - * ： 对所以服务都应用当前降级类
     *  - null : 对所以服务都应用当前降级类
     * @return
     */
    @Override
    public String getRoute() {
        return "item-service";
    }

    /**
     *
     * @param route
     * @param cause
     * @return
     */
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR; //服务器内部错
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {
                // 用来关闭下面的流
                // BAIS 不占用底层系统资源，不需要关闭
            }

            @Override
            public InputStream getBody() throws IOException {
                // JsonResult -{code: 500 ,msg: xxx,data: null}
                String json = JsonResult.build().code(500).msg("后台服务出差，请稍后重试！").toString();
                // 字符串变成byte【】数组，封装BAIS
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {  // 协议头
                HttpHeaders h = new HttpHeaders();
                h.add("Content-Type","application/json;charset=UTF-8");
                return h;
            }
        };
    }
}